fix(napi-derive): should transform struct case on Impl

examples/napi/__test__/typegen.spec.ts.md

@@ -217,7 +217,7 @@ Generated by [AVA](https://avajs.dev).
     export type Blake2bHasher = Blake2BHasher␊
     /** Smoking test for type generation */␊
     export class Blake2BHasher {␊
-      static withKey(key: Blake2bKey): Blake2BHasher␊
+      update(data: Buffer): void␊
     }␊
     export type Blake2bKey = Blake2BKey␊
     export class Blake2BKey { }␊

examples/napi/index.d.ts

@@ -207,7 +207,7 @@ export class Bird {
 export type Blake2bHasher = Blake2BHasher
 /** Smoking test for type generation */
 export class Blake2BHasher {
-  static withKey(key: Blake2bKey): Blake2BHasher
+  update(data: Buffer): void
 }
 export type Blake2bKey = Blake2BKey
 export class Blake2BKey { }